Sandwich–like NiFe layered double hydroxides/Co_1-xS (NiFe LDH/Co_1-xS) heterostructure with synergistic electrocatalytic effects for highly efficient oxygen evolution reaction is successfully prepared by electrodepositing Co_1-xS on the surface of NiFe LDH grown on nickel foam (NF). The NF supported heterostructure possesses three-dimensional (3D) catalytic space and strained heterointerface. Thereinto the Co_1-xS layer provides extra active sites over the original NiFe LDH. Besides, the lattice mismatch in the surface of NiFe LDH induces the formation of lattice strain in Co_1-xS, which thus modulates the local electronic structures. Density functional theory (DFT) calculations validate that the strained heterointerface has advantageous OER activity. From the results of electrochemical tests, the NiFe LDH/Co_1-xS possesses large number of active sites and fast charge transfer. More importantly, optimized structure and interface characteristics improve the electrocatalytic stability, resulting in long–term durability with almost no attenuation after 150 h constant current test.

通过将Co _1-x S电沉积在NiFe LDH的表面上，成功制备了具有协同电催化作用的三明治状NiFe层状双氢氧化物/ Co _1-x S（NiFe LDH / Co _1-x S）具有协同电催化作用以实现高效氧释放反应。在镍泡沫（NF）上生长。NF支撑的异质结构具有三维（3D）催化空间和应变异质界面。其中的Co _1-x S层在原始NiFe LDH上提供了额外的活性位。此外，NiFe LDH表面的晶格失配引起Co _1-x晶格应变的形成。S，从而调制局部电子结构。密度泛函理论（DFT）计算验证了应变异质界面具有有利的OER活性。从电化学测试的结果来看，NiFe LDH / Co _1-x S具有大量的活性位点和快速的电荷转移。更重要的是，优化的结构和界面特性可改善电催化稳定性，从而获得长期的耐用性，并且在150 h恒流测试后几乎没有衰减。